Andrew Tyrie: Fresh From The HBOS Debacle, Now Serious About Reform

London's mayor, Boris Johnson, famously called on "banker-bashers" to stop.

Former Barclays boss Bob Diamond told the Treasury select committee that there had been enough remorse. It is in large part due to Andrew Tyrie, Conservative chair of that committee, that a brand new apology for the disasters of 2008 was offered up this month.

Former HBOS chief executive Sir James Crosby gave up a third of his £580,000 pension and has also offered to hand back his knighthood after a damning report by the banking commission Tyrie chairs said HBOS bosses were "delusional" and guilty of a "colossal failure of management". Is this sufficient penance, does Tyrie think? "I think he's done the right thing, acted honourably."

For a man who has shed more light on what really went wrong in Britain's banks than any of the regulators, Tyrie is careful with his words. He won't say whether he hopes Vince Cable will ban the trio credited with sinking HBOS from acting as directors – a move that would see Andy Hornby, one of the three, stripped of his current job as chief executive of bookmaker Coral. Nor will he comment on the resignations this week of Rich Ricci and Tom Kalaris, heads of investment banking and wealth management at Barclays. Nor will he say anything at all about Lord Green, chief executive and chair of HSBC when the bank laundered billions for drug cartels, and now a peer and trade minister.

But there is no doubt Tyrie is serious about banking reform. His banking commission's final report, due next month, is awaited with great interest and not a little anxiety – not least by George Osborne. Tyrie has forced the chancellor's hand once already, with a demand that the "ringfence" between banks' retail and investment activities called for in last year's Vickers report be "electrified". It is a turn of phrase that has now entered the banking lexicon, and one which Tyrie says may have come to him while out running beside one of the electric fences in his West Sussex constituency.

Though its contents remain secret, Tyrie hints that the report will contain new measures on restricting pay, but not bonuses, that the "approved persons" list managed by regulators will become far more robust, and that regulators will be offered protection from the lobbying might of the banks.

"What really sticks in the craw of the electorate," he says, "is that what you and I would consider to be very serious offences have been committed, and yet there doesn't seem to be an orange jumpsuit on anyone – although there may yet be with Libor." New laws, he says, may not be the solution because more people could have been prosecuted under existing laws had the regulators had the will and the resources.

"The sheer scale and variety of things that the banks got up to is quite extraordinary. This isn't a few bad apples in a very large barrel – these are large numbers of people over very long periods, able to conduct malpractice, market abuses and what you and I would call simple fraud."

Tyrie is an unlikely radical. He went to public school and both Oxford and Cambridge and worked for 20 years for BP and as an adviser to Nigel Lawson – now a member of the Lords and a vocal member of the banking commission – before being elected to his safe Chichester seat in 1997. In opposition, he ran two leadership campaigns for Ken Clarke. He opposed the Iraq war, and asked a series of searching questions about the UK's role in extraordinary rendition of terrorist suspects that led to David Miliband being forced to retract untrue statements made by his predecessor as foreign secretary, Jack Straw. Tyrie says he was punished for opposing the war by not being given an office in Portcullis House. Instead, he says, he was stuck in a corner where the authorities knew he would be disturbed by a pneumatic drill, but things have since improved and he now has plenty of space and a river view.

He was probably seen as awkward. He is a climate change sceptic, has been nicknamed "Andrew Tiresome", and in 2010, despite his ambition, he failed to get a government job. "Do I look like a toady to you?" he says with a grin.

Instead he beat fellow Conservative Michael Fallon in the ballot for Treasure committee chair, and built it into a power base. In the wake of the Libor scandal, when the government rejected Labour's calls for a judge-led public inquiry into banking, it was Tyrie who managed to command sufficient confidence across parties that a parliamentary commission could do the job. The commission has increased his influence further. It has 20-30 staff plus advisers, and its own QC, Rory Phillips. In six months, the commission took 168 hours of evidence.

Proud of his maverick status, Tyrie is not afraid to fire a shot across the bows. The list of questions about government-backed mortgage lending in his select committee report on the budget will not be welcomed in No 11. Nor will the committee's demand, after key budget details appeared in the Evening Standard before the chancellor had even stood up, that pre-briefing journalists on the budget should stop.

He quotes Keynes when asked about the government's focus on austerity – "when the facts change, I change my mind" – and agrees it's possible the policy may turn out to be wrong: "Yes, that's a risk, and that's what happened in the 1930s. When economists in their lofty way say that the policy-making environment is challenging and subject to a high degree of uncertainty, that's their way of saying the same thing. It may be very boring to hear this but I don't think there would be a great deal of difference on the central issue, that is about the degree of fiscal tightening, whoever was in power, whether Con, Con-Lib, Lib-Lab or Lab."

He also thinks Osborne may have given too much power to the Bank of England under the reformed City regulatory structure, and that the governor's enhanced role could be a "point of systemic risk". But luckily the Treasury select committee exists to scrutinise: "It is absolutely vital that we do that job with more rigour than ever before."